Toxicants are widely distributed in plants and plant products, including intentionally added, incidentally added, and naturally occurring food toxicants. This review covers the toxicity of some food additives: the distribution, residues, toxicity, and methods of removal of some pesticides and toxic metals; and the presence of naturally occurring toxicants in plants and plant products. Extensive review has been done, particularly on natural toxicants. However, there are still extensive gaps in our knowledge pertaining to effect upon the health of many of the substances known to be present in natural plant food products, as well as even the identity of many natural chemical components of plant foods and their potential toxicological significance. An understanding of their presence, formation, and toxicity is important as far as public health is concerned.